Cross-bar switch system with several markers



May 25, 1954 A. c. JACOBAEUS CROSS-BAR SWITCH SY Filed April 10, 1950 STEM WITH SEVERAL MARKERS 4 Sheets-Sheet l y 19154 A. c. JACOBAEUS 2,679,552

CROSS-BAR SWITCH SYSTEM w ITH SEVERAL MARKERS Filed April 10, 1950 4 Sheets-Sheet 2 x. M2 M22 23 M24 I e @173 y 5, 1954 A. c. JACOBAEUS 2,679,552

CROSS-BAR SWITCH SYSTEM WITH SEVERAL MARKERS Filed April 10, 1950 4 Sheets-Sheet R1 R2 R3 R4 R5 R6 R7 R8 R9 y 1954 .A. C-JACOBA'EUS BAR SWITCH SYSTEM WITH SEVERAL MARKERS cRoss- 4 Sheets$heet 4 Filed April 10, 1950 -ZZLU6J2IZOZD 4:2 C. 7dcofi 62 6 106 R20 R28 k29 R47 Patented May 25, 1954 UNITED STATES PATENT OFFICE 2,679,552 CROSS-BAR SWITC SEVERAL Anton Christian assignor to Telefona Stockholm, Sweden,

.lacobaeus, Stock ktiebolaget H SYSTEM WITH MARKERS holm, Sweden, L M Ericsson, company of Sweden Application April 10, 1950, Serial No. 154,935

Claims priority,

2 Claims.

The present invention relates to automatic telephone systems with selecting units comprising primary and secondary cross-bar switches and several markers. In such a system several anged simultaneously but at a'time may be connected to it. There are each selecting unit for outgoing lines and therefore a marker, which is setting a connection from a calling line connected to a certain selecting unit selecting units.

Each one of the selecting units serves a number of incoming or outgoing lines. A calling line is over special means connected to one of the markers, said marker thereby being operated to mark on one side a group of .lines or a certain line to which the call is directed, and the selecting unit to which this line pertains, and on the other side the selecting unit to which the calling line pertains. Each selecting unit is proaid relay for the ed line or group of e relay for the selecting unit ith primary are connected. The in application Sweden May 6, 1949 nected over register-finders RS to registers REG, which are set by signals from that an outgoing line T or a group of outgoing is marked. After a register REG has been ter indicating its AC the call multaneously tions between other selecting units.

Fig. 1 shows a selecting unit consisting of crossbar switches Ki-Kt for incoming lines and cor- C in Fig. 5.

rs setting connecprised in Fig. 1. In Fig. and L t a relay set for the same line. The line L is over the Wires ari connected to the contacts in the cross-bar switch Kl in Fig. 1 corresponding to the selecting magnet Si I. When a call comes in over line L the relay set LR is connected to a register REG over a register-finder Signals thereafter 0 of lines is marked.

lines Tl'1" in Fig. within said group is to be selected and conne with line L. The register REG is connected to a marker over a selector MS. The marker according to Figs. 3-4 comprises a registering device MR, which is set from the register REG and points out the called group of lines,

line cted a selecting unit for.

erated from the r er one of the contact rows ala3. Each of the relays pertains to a selecting unit for incoming lines. In this case relay R9 is to the selecting unit sh the calling line L is iiil-l95 are closed.

closed if the two select own in Fig. l and to which connected. The contacts The following circuit is ing units in Figs. 1-2 are the connected line so free: contacts II and I5, winding on relay MI2, rectifier EI, wire 9, contacts I95 and 22I, wire r, rectifier E2, winding on relay M22, contacts 25 and H to negative. Relays MI2 and M22 attract their armatures. Contacts I3-20 and 23-30 are operated. The circuit is switched by contacts I4 and 24 to relays MI I and M2I, which operate. Contacts II-I2 and 2I-22 are operated. The selecting units in Fig. l and Fig. 2 are thereafter marked busy and other markers corresponding to the relays MI3-MI 4 and M23- M24 cannot be connected. The following circuit is closed: contacts I2 and I6, wire 1, winding on relay R0, wire s, contacts 26 and 22, to negative. Relay R6 attracts its armature. The contacts I6I-I64 are closed. The following circuits are closed:

(1) The selecting magnet SII in Fig. 1 is energized over contact I62, contact row bI in MS, register REG, RS and LR and wire (1. Contact H is closed. Relay KII operates. Contacts IIII-I I9 are closed.

(2) Relays V3 and V4 in Fig. 2 are operated over contact I63, contacts in MR and wire :1: among the indicating wires 86 and 13-16 are closed and indicate which one of lines TI-T4 pertains to the called group of lines.

(3) Relay R4I is operated over contact I54, wire w, contacts 203-293; The contacts 4II- 4I9 are closed, the test relays R20-R29 thereby being connected over the wires h-lc and contacts I8-20 to the test wires for the connecting paths which can reach line L through the selecting unit in Fig. 1.

(4) Relay R40 wire and contacts 303-393. 40I-405 are operated.

(5) Relay R2 is also operated over contact I64 in the following circuit: contacts I64, I20, I22, I33, I43, I52, rectifier E3, contacts I56, I46 and I36, winding on relay R2 to negative.

The following circuit is closed: contacts I6I, 222, I24 and I9I, wire it, winding on relay VI to negative. Relay VI attracts its armature. Contacts 33-35 are operated. Simultaneously, relay R3 receives current over contact I23. Relay R3 operates and relay R2 is held. Contacts I3I-I39 are operated. The following circuit is closed: contact 35 in Fig. 1, wire q, contacts I94, I3I and I2I, winding on relay RI, wire i, contact M9 to negative. Relay RI operates. Contacts I00 and I are actuated. Relay R2 releases its armature whilst relay R3 is held in the following circuit: contacts I64, I00, I56, I46 and I35, winding on relay R3 to negative. When relay R2 released its armature, relay VI released its armature and relay V2 was operated in a circuit over contacts I and I31. Contacts 43-45 in Fig. l are closed. When contact I2I opens, relay RI releases its armature. Relay R4 now receives current over contacts I20, I22 and I34 and attracts its armature simultaneously with relay R3 being held. Contacts I4 I-I49 are operated. Relay RI is operated again, this time in a circuit over contact 45, wire q, contacts I94, MI and I32. Relay R3 releases its armature when contact I20 is operated and relay R4 is held over contacts I00, I56 and I45. In this way relays VI-V2 are operated one after the other until all relays in the relay chain R2-R5 have been operated or relay R4I in Fig. 4 releases its armature, which takes place when a free connection between line L and one of the lines is simultaneously operated over The contacts :r-z. Contacts 03- battery V+,

in Fig. 4, windings TI-T4 is found, whereby one of the relays R20- R29 attracts its armature.

In the relay chain R2-R5 each selecting unit for outgoing lines D-F in Fig. 5 has a row of contacts I25-I41, I21-I48 or I29-I43. The wires coming from said contact rows can be connected to relays, VI-V2, in any of the selecting units for incoming lines, A-C in Fig. 5, over contacts, for example I9 I-I 94 on relays RI-RB. If the relay chain is passed without any free connection being found, relay R5 is actuated and a circuit is closed to an alarm device AL. Relay R5 is thereby held in a circuit over contact I53.

During the searching process, the following circuits are closed for the test relays R20-R29 when operates: contacts 99-90 in Fig. 2, circuits connected in parallel over contacts 33- 98, rectifiers eo-el, contacts 84-, 14-86-16, 8I-82-II-I2, selecting magnets S8I-S'II, contacts 5I-50, selecting magnets S5I-S50. contacts 34-33 in Fig. 1, 32-42, selecting magnets S3I- S4I, contacts I09-IOI, II9-IIO, III-20, wires n-k, winding on relays R20-R29, contacts 4I4-4I2, to negative. If all the connecting means are free, all the relays R20-R29 operate. We suppose that at least relay R20 attracts its armature. The contacts 20I-203 are operated. Relay R4I becomes currentless and releases its armature. All the test circuits are broken at contacts 4I2-4I4' and only the relay which is operated and lies first in the relay chain R20-R29 is held. In the present case relay R20 is held over contact 202. The following circuit is closed: from the positive pole on an auxiliary resistance rI, contacts 4H and 2M, wire 71., contacts 20, I I0 and IN, selecting magnet S4I, contacts 42 and 33, selecting magnet 550, the circuits connected in parallel over contacts 5I-50, selecting magnets SBI-S'II, contacts 8I-82-1I-12, 14-84-16-85, windings I and II on relays P20-P2I, contacts 93-98-90-939. The windings II on relays P20-P2I have such a high resistance, that none of the selecting magnets S50, S'II or S8I can be connected in series with them. Relays P20-P2I form a relay chain, in which only one relay at a time can be operated. We suppose that relay P20 attracts its armature but not relay P2I. Contacts 30-94 are operated. The following circuit is closed: contacts 99 and 94, winding I on relay P20, the parallel circuits over contacts 84-14 and 82-8I. selecting magnet SBI, contact 5I, selecting magnet S50, contacts 33 and 42, selecting magnet S4I, contacts IOI, H0 and 20, wire it, contacts MI and 4H, resistance rI to V+ Winding I on relay P20 has a low resistance, wherefore the selecting magnets SBI, S50 and SM attract their armatures. The contacts 8I0, 5I0 and M0 are closed.

When relay P20 attracts its armature the selecting magnets B8I-B82 are connected to the test relays R30 -R39, whereby the following parallel circuits are closed: contacts 403-405 on relays R30-R39, wires u-v, contacts 28-30, III-32, 83-13, operating magnets BBI-BBI, to negative. Said windings on relays R30-R39 have such a high resistance that the operating magnets B8I-B82 have not yet been operated.

All the operating switches KI-KS are of the multiple contacts the operating magnet attracts its armature. This is indicated in Figs. 1-2 by a connection between each operating magnet and the thick line which, in the symbol for a cross-bar switch, represents magnets in the cross-bar held during a call over one which are closed, when the multiple field of the operating magnet. When one of the operating magnets B1|B12 and Edi-i332 is busy, is connected to the winding of the operating magnet, wherefore none of the relays EEO-R39, which at testing are connected to a busy operating magnet; can be operated. Those of relays R30R39, which are connected to a free operating magnet, on the other hand, operate. We suppose that at least relay R39 attracts its armature. 39l-393 are operated.

the operating circuits for relays BSD-R39, all of which, release their armatures. contact 392. During the operating time for relay R39 and the release time for relay R40, the selecting magnets 88!, and SM have completed their operation, and the corresponding operating magnets B55, .8 32, and BH now simultaneously attract in the following circuits: contact 40L Wires m and t, contacts I! and 21, M0, 500 and BI I, B42, and Bl, to negative. Simultaneously, operating magnet B11 is also operated in the following circuit: contact 40!, contact 39!, wire 1), contacts 30, 92 and 73, operating magnet BBI, to negative.

The operating magnets B81, B51 and B42 and BH are held over their own contacts in series with one Of the wires a-c in Fig. 1. Such a switching process thereby takes place in the line equipment LR, that the register EEG and the marker are released. A communication is there after connected between the line L and the line Tl in Fig. 2 over the operating magnets Bl I, B42, B5! and Bill.

If relay VI I claim:

1. In an automatic telephone system a first and a second selecting unit connected by links, a calling line connected to said first selecting unit and a called line connected to said second selecting unit, a plurality of registering devices, a series of relays for each of said selecting units including a test relay for each of said registering devices for marking the selecting unit busy when operated, means connecting one of said ing said test relays in said first and said second selecting units, said two test relays operating simultaneously when both said selecting units are idle, and connecting conductors for operation of said selecting units to the registering device, and means selecting one of said links and establishing a communication between said calling line and said called line over said selecting units and the selected link.

2. In an automatic telephone system, two groups of selecting units, each unit including primary and secondary cross bar switches connected by links, at least one calling line connected one of said groups, a group of called lines connected to one of said selecting units in the other of said groups, intermediate links connecting the selecting unit for the calling line to the selecting unit for the called group of lines, a register, a register selector, a circuit connecting said register through said the calling line for setting the register by signals from the calling line in accordance with the called telephone number designating the called group of lines, a plurality of markers, a marker selector, a circuit connecting said register through said marker selector to one of the markers for transmitting signals from the register to the marker designating the selecting unit for the calling line and the selecting unit for the called group of lines and said group of called lines, a series of relays for each of said selecting units including a test relay for each of said markers for marking the selecting unit busy when operated, a test circuit closed by said marker including said test relay in the selecting unit for the calling line and corresponding test relay in the selecting unit for the of lines, said two test relays operating simultaneously when both said selecting units are idle and connecting conductors for operation of said selecting units to the marker, and means in said marker selecting one link in each of the two selecting units and one of said intermediate links and one line within said called group of lines and establishing a communication between said calling line and the selected line in said called group of lines over the selected links.

References Cited in the file of this patent UNITEDSTATE'S PATENTS Number Name Date 2,201,986 Collis May 28, 1940 2,585,904 Busch Feb. 19, 1952 

